His alter ego Mr Selfridge may have taken some time to adapt to British ways, but Jeremy Piven can't get enough of the UK's accents and royal family. The actor even likes our "exciting" weather, as Keeley Bolger discovers.
As the star of cult TV hit Entourage, about an LA movie star and his inner circle, you wouldn't think Jeremy Piven would be lacking in street cred.
But the actor reckons his young nieces only started to respect him when he took on the role of Harry Selfridge, in the popular ITV period drama, Mr Selfridge.
"My nieces, Pearl and Lily Rose, think Uncle Jeremy is kind of cool when Hanukkah and Christmas come around, because I bring them gifts," says the 48-year-old, laughing. "Other than that, it's a lot of eye-rolling."
Until now, that is. "Suddenly they're watching Mr Selfridge every week and they love it! It's really cool that I finally got some love and respect from my nieces. That's huge," he adds, smiling. "I believe I've finally succeeded."
His nieces may not always approve, but Piven, speaking from the set of the ITV series today - a lofty old carpet warehouse where he's perched on an ornate seat - has enjoyed an illustrious career.
Born in Manhattan and raised in Illinois, his first job was a role in the 1986 film Lucas (also starring Charlie Sheen), which he took aged 18 to support himself through university.
His other movie credits include Rush Hour 2, Serendipity and Black Hawk Down, and he won three Emmy Awards for his portrayal of neurotic Hollywood agent Ari Gold in Entourage.
But it's as Mr Selfridge that he's made a name for himself in the UK and, crucially, won his mum's praise.
"All I know is that this [Mr Selfridge] is the first time my mother has given me amazing feedback," says Piven, who is kitted out in a suave three-piece suit. "Her friends love Mr Selfridge so that's incredible, it's that generation."
'Generation' is a nicely vague term that Piven likes to use with his mother, a "great woman" who has just written a book about acting (she's the director, teacher and actress Joyce Piven).
"I wouldn't be able to tell you how old my mother is," he adds, smiling. "That's the one vanity my mum has. Everything else is fair game.
"I didn't know how old my mum was until I was in my thirties. She was 39 and then I was 39, so it's all very confusing. I've actually lapped my mother. The first son ever to be older than his mother in the history of mankind."
Family is very important to Piven, who spends "six or seven months" in the UK filming the drama series, which returns to the small screen this month.
"I miss my mum so much," he says. "She'd like to meet the Queen, but she doesn't realise that I don't know the Queen."
Her Majesty herself might be a tall order, but Piven has already met Princes William and Harry.
"We met at a polo match last year, where they were both playing," he recalls. "They were both really good, surprisingly good, and they very humbly said they were not. I was like, 'You can't say you're not good, because I just saw you and you're amazing!'
"I can see why everyone's in love with them. They're very present, humble and sweet."
The actor, who is a keen drummer and plays in a band called Bad Decisions back in the States, has also met some British rock royalty.
"I went to see the Rolling Stones," he reveals. "I was hoping Charlie Watts would sprain something, so I could step in for a moment. Because I'm ready.
"I asked Ronnie Wood if I could sit in for Charlie. He was very polite and said I could come over and play with him. But listen, Charlie hasn't taken five [minutes off] in 50 years, so I don't think he's going to now. He'll play through 'til he's 110."
In the meantime, Piven's content playing the groundbreaking shopkeeper and he's enjoying his time in Blighty, even taking a holiday in the New Forest.
"One of the great things [in the UK] is to hear all the accents," says the actor, who reveals that he enjoys cycling around London.
"To get the northern accent and even neighbourhood to neighbourhood, accents switch. It's really fun to get to know where each accent comes from."
He's been party to a fair few of them, often from his trips to Selfridges for a round of shopping. "People here are very respectful," he says. "But I did have this woman come up to me and ask whether there was any way I could talk to my workers, because she had a manicure and pedicure at Selfridges and it hadn't held up. That was cute."
Even the great British weather ("You get four seasons in a day; it's hailing, then it's a monsoon. It's exciting") hasn't put him off being here.
"I love it," Piven insists. "The cool thing is that I matched up perfectly with Harry Selfridge.
"I was an American making my way here, as was he, so we were kind of mirroring each other. I didn't look too far for inspiration."
EXTRA TIME - SHOPS ON SCREEN
* Are You Being Served? (1972-1985) - The ultra-traditional department store (in which a young Wendy Richard 'worked' in the ladies department) was the perfect hotbed for in-fighting, mishaps and rather odd selling techniques.
* Open All Hours (1976-1985) - Grocer Albert Arkwright, deftly played by Ronnie Barker, made an art form out of miserliness in this classic sitcom, which starred David Jason as Arkwright's long-suffering nephew Granville.
* Miranda (2009-) - Stevie and Miranda may not know much about business plans and sales projections, but the best pals and colleagues certainly make work at the Joke Shop seem fun, with their singing and comical bickering.
* Trollied (2011-) - Jane Horrocks does her best to manage her unruly workforce in this comedy, about a fictional supermarket in Warrington, called Valco.
* The Paradise (2012-) - This lavish drama, about the trials and tribulations of the staff at the country's first department store, is set in 1870s Britain.
* Mr Selfridge returns to ITV on Sunday, January 19